Fotodiox Pro PocketWonder Elite 4-in-1 with TTL pass-thru, Radio Wireless Trigger Starter Kit (3C), fits Canon Pro Cameras (1 TX + 1 RX), Shutter Release, TTL pass-through Premium Grade 4-in-1 Multi-Function Radio Trigger for Flash, Strobe and Camera, 2.4GHz Radio Frequency with range up to 300ft Allows TTL pass-through on the Transmitter, Sync Speed of 1/250 sec, when in "flash" mode. Wake-up function to wake up majority of flash from "sleep" In "camera" mode, remote is able to do AF, remote trigger. Also continuous shooting and "Bulb" by press and hold the trigger bottom for 2 sec, and press again to stop Power Switch on both RX and CX to conserve energy and for storage. Expandable with additional Receiver available for purchase 24 Month Manufacture Warranty